from diceplayer.config import PlayerConfig
from diceplayer.logger import logger

from pydantic import BaseModel, Field
from typing_extensions import Self

import random
from enum import StrEnum
from pathlib import Path
from typing import Annotated, Any, Literal, TextIO


_ALLOWED_DICE_KEYWORD_IN_ORDER = [
    "title",
    "ncores",
    "ljname",
    "outname",
    "nmol",
    "dens",
    "temp",
    "press",
    "seed",
    "init",
    "nstep",
    "vstep",
    "mstop",
    "accum",
    "iprint",
    "isave",
    "irdf",
    "upbuf",
]


class DiceRoutineType(StrEnum):
    NVT_TER = "nvt.ter"
    NVT_EQ = "nvt.eq"
    NPT_TER = "npt.ter"
    NPT_EQ = "npt.eq"


def get_nstep(config, idx: int) -> int:
    if len(config.dice.nstep) > idx:
        return config.dice.nstep[idx]
    return config.dice.nstep[-1]


def get_seed(config) -> int:
    return config.dice.seed or random.randint(0, 2**32 - 1)


def get_ncores(config) -> int:
    return max(1, int(config.ncores / config.dice.nprocs))


# -----------------------------------------------------
# NVT THERMALIZATION
# -----------------------------------------------------
class NVTTerConfig(BaseModel):
    type: Literal[DiceRoutineType.NVT_TER] = DiceRoutineType.NVT_TER

    title: str = "NVT Thermalization"
    ncores: int
    ljname: str
    outname: str
    nmol: list[int]
    dens: float
    temp: float
    seed: int
    init: Literal["yes"] = "yes"
    nstep: int
    vstep: Literal[0] = 0
    isave: int
    upbuf: int

    @classmethod
    def from_config(cls, config: PlayerConfig, **kwargs) -> Self:
        return cls(
            ncores=get_ncores(config),
            ljname=str(config.dice.ljname),
            outname=config.dice.outname,
            nmol=config.dice.nmol,
            dens=config.dice.dens,
            temp=config.dice.temp,
            seed=get_seed(config),
            nstep=get_nstep(config, 0),
            isave=config.dice.isave,
            upbuf=config.dice.upbuf,
            **kwargs,
        )


# -----------------------------------------------------
# NVT PRODUCTION
# -----------------------------------------------------
class NVTEqConfig(BaseModel):
    type: Literal[DiceRoutineType.NVT_EQ] = DiceRoutineType.NVT_EQ

    title: str = "NVT Production"
    ncores: int
    ljname: str
    outname: str
    nmol: list[int]
    dens: float
    temp: float
    seed: int
    init: Literal["no", "yesreadxyz"] = "no"
    nstep: int
    vstep: int
    isave: int
    irdf: Literal[0] = 0
    upbuf: int

    @classmethod
    def from_config(cls, config: PlayerConfig, **kwargs) -> Self:
        return cls(
            ncores=get_ncores(config),
            ljname=str(config.dice.ljname),
            outname=config.dice.outname,
            nmol=config.dice.nmol,
            dens=config.dice.dens,
            temp=config.dice.temp,
            seed=get_seed(config),
            nstep=get_nstep(config, 1),
            vstep=config.dice.vstep,
            isave=max(1, get_nstep(config, 1) // 10),
            upbuf=config.dice.upbuf,
            **kwargs,
        )


# -----------------------------------------------------
# NPT THERMALIZATION
# -----------------------------------------------------
class NPTTerConfig(BaseModel):
    type: Literal[DiceRoutineType.NPT_TER] = DiceRoutineType.NPT_TER

    title: str = "NPT Thermalization"
    ncores: int
    ljname: str
    outname: str
    nmol: list[int]
    dens: float
    temp: float
    press: float
    seed: int
    init: Literal["yes", "yesreadxyz"] = "yes"
    nstep: int
    vstep: int
    isave: int
    upbuf: int

    @classmethod
    def from_config(cls, config: PlayerConfig, **kwargs) -> Self:
        return cls(
            ncores=get_ncores(config),
            ljname=str(config.dice.ljname),
            outname=config.dice.outname,
            nmol=config.dice.nmol,
            dens=config.dice.dens,
            temp=config.dice.temp,
            press=config.dice.press,
            seed=get_seed(config),
            nstep=get_nstep(config, 1),
            vstep=max(1, config.dice.vstep),
            isave=config.dice.isave,
            upbuf=config.dice.upbuf,
            **kwargs,
        )


# -----------------------------------------------------
# NPT PRODUCTION
# -----------------------------------------------------
class NPTEqConfig(BaseModel):
    type: Literal[DiceRoutineType.NPT_EQ] = DiceRoutineType.NPT_EQ

    title: str = "NPT Production"
    ncores: int
    ljname: str
    outname: str
    nmol: list[int]
    dens: float
    temp: float
    press: float
    seed: int
    init: Literal["yes", "yesreadxyz"] = "yes"
    nstep: int
    vstep: int
    isave: int
    irdf: Literal[0] = 0
    upbuf: int

    @classmethod
    def from_config(cls, config: PlayerConfig, **kwargs) -> Self:
        return cls(
            ncores=get_ncores(config),
            ljname=str(config.dice.ljname),
            outname=config.dice.outname,
            nmol=config.dice.nmol,
            dens=config.dice.dens,
            temp=config.dice.temp,
            press=config.dice.press,
            seed=get_seed(config),
            nstep=get_nstep(config, 2),
            vstep=config.dice.vstep,
            isave=max(1, get_nstep(config, 2) // 10),
            upbuf=config.dice.upbuf,
            **kwargs,
        )


DiceInputConfig = Annotated[
    NVTTerConfig | NVTEqConfig | NPTTerConfig | NPTEqConfig,
    Field(discriminator="type"),
]


def _serialize_value(value: Any) -> str:
    if value is None:
        raise ValueError("DICE configuration cannot serialize None values")

    if isinstance(value, bool):
        return "yes" if value else "no"

    if isinstance(value, (list, tuple)):
        return " ".join(str(v) for v in value)

    return str(value)


def write_dice_config(obj: DiceInputConfig, io_writer: TextIO) -> None:
    values = {f: getattr(obj, f) for f in obj.__class__.model_fields}

    for key in _ALLOWED_DICE_KEYWORD_IN_ORDER:
        value = values.pop(key, None)
        if value is None:
            continue
        io_writer.write(f"{key} = {_serialize_value(value)}\n")

    io_writer.write("$end\n")


def write_config(config: DiceInputConfig, directory: Path) -> Path:
    input_path = directory / config.type

    if input_path.exists():
        logger.info(
            f"Dice input file {input_path} already exists and will be overwritten"
        )
        input_path.unlink()
    input_path.parent.mkdir(parents=True, exist_ok=True)

    with open(input_path, "w") as io:
        write_dice_config(config, io)

    return input_path